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If z is a complex number such that $|\mathrm{z}| \geq 1$, then the minimum value of $\left|\mathrm{z}+\frac{1}{2}(3+4 \mathrm{i})\right|$ is

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  • #12502
    UPLIFTJEE
    Keymaster

    If z is a complex number such that $|\mathrm{z}| \geq 1$, then the minimum value of $\left|\mathrm{z}+\frac{1}{2}(3+4 \mathrm{i})\right|$ is [JEE (Main) 01 Feb 2024 S II]
    (A) 2
    (B) $\frac{5}{2}$
    (C) $\frac{3}{2}$
    (D) 3

    #12503
    UPLIFTJEE
    Keymaster

    Solution

    According to the question,

    $|\mathrm{z}| \geq 1, \mathrm{z}$ lies on or outside the circle whose radius is 1 and centre $(0,0)$
    $\left|\mathrm{z}+\frac{1}{2}(3+4 \mathrm{i})\right|=\left|\mathrm{z}-\frac{1}{2}(-3-4 \mathrm{i})\right|=$ distance between z and $\left(-\frac{3}{2},-2\right)$
    Min. value of $\left|\mathrm{z}+\frac{3}{2}+2 \mathrm{i}\right|$ is zero
    No options are matched so this question was dropped

    #12504
    UPLIFTJEE
    Keymaster

    Answer

    Bonus

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